Bullet type casing perforator



Filed Nov. 2, 1938 diag @taf/?- i Patented May 14, 1940 UNITED STATES PATENT UFFICE BULLET TYPE CASING PERFORATOR Kuhn Calvert, Chauk, Burma, India Application November 2, 1938, Serial No. 238,296

12 Claims. (Cl. 164-05) The invention relates to improvements in aD- intermediate SeCtiOnS f the Del'fOIaOI ShOWiIlg paratus for perforating a well casing and has for the spiral orientation of the gun units and their an object to provide a portable gun unit which association each with a powder chamber;

will re a plurality of projectiles under control Figure 3 is a vertical sectional View showing 5 of an operator at some distance from the unit. the improved iiring plug emplyed in the present 5 When the' production of an oil well has become perforator; exhausted the procedure resorted to in an eiort Figure 4 is a. sectional view taken substantially to secure additional oil from the well consists in along lille 4-4 0f Figure 2 and ShOWing the arperforating the casing at different levels where rangement 0f the gun units With IeSDeCG t0 the oil bearing sands have been drilled through. The central firing bOIe; and 10 invention provides an improved casing perforator Figure 5 iS another transverse SeCtiOnal View for the purposes described having a plurality of taken along line 5--5 0f Figure 2 Showing the explosive charges for firing perforating means in removable loading plug fOr the DOWdeI Chambersthe form of bu11ets and which may be fired elec- Referring t0 the drawing, the perforating unit 15 tricauy after the unit has been lowered in the consists of a head piece I0, a part Il providing 15 well casing to the desired depth. an ignition chamber, an intermediate section I2,

Another object of the invention is to provide a a lower intermediate section I3 of identical conbullet type perforator which can be loaded in a, struction, and a bottom or nose member I4, all of manner whereby the operator will be absolute1y said parts being formed of metal such as steel or safe from premature explosions of the charges. a steel alloy. As shown in Figure 1, the parts I0 20 Another object of the invention is to provide a and II are suitably threaded at I5. Part II probullet type perforator wherein the powder chamvides a cable pin I6 to which is suitably fastened bers for the gun units can be lled with powder the cable I8 extending through the head piece I0. as the last operation in preparing the gun for By means of the cable the casing perforator is iiring. suspended and lowered into a well casing. 'I'he 25 Another object is to provide a perforator con end of head piece II] is threaded for receiving the sisting of sections of identical construction and cap 20 which forces member 2| into the recess which can be varied in number sn that the presprovided in the end of said head piece and which ent perforator may have a length for firing the thus applies pressure to packing conned within desired number of charges for any particular persaid recess forming a stung box for the cable 30 forating operation. I8, thereby sealing the interior of the chamber -Another object is to provide a well casing performed by parts I0 and II from external hydroforator having a powder chamber for each gun static pressure. unit which will be accessible from the exterior of Part II of the casing perforator is provided the perforator after the gun unit is in place so with a ring plug indicated in its entirety by nu- 35 that the same 'may be filled with powder and meral 22 and which is shown in detail in Figure 3. wherein all the powder chambers are connected Said plug comprises a body portion 23 having a with a central firing bore. vertical extending part 24 externally threaded,

Another object of the invention is to provide a whereby the ring plug may be secured in place 40 well casing perforator of relatively simple conwithin the recess therefor formedinpart II. The M struction which will operatewith high efciency central electrode 25 extends through the body and fulfill all requirements of service. portion and depends some distance beyond the With these and various other objects in view, same. The ground electrode 26 also depends a the invention may consist of certain novel fealike distance from the body portion and said tures of construction and operation as will be electrode is suitably secured thereto by the nut 45 more fully described and particularly pointed out 21 having threaded engagement with part 24. in the specification, drawing and claims ap- The fuse wire 28 connects the central electrode pended hereto. Y andthe ground electrode and when energized said `In the drawing, which illustrates an embodifuse wire will ignite the explosive powder in ment ofthe invention, and wherein like reference chamber 30 within which the electrodes are lo- 50 characters are used to designate like partscated.

Figure 1 is an elevational view of the bullet The intermediate sections of the perforator type casing perforator of the invention showing each have a recess 3|, Figure 2, formed in one a portion of the head end thereof in section; end thereof, which is internally threaded as at Figure 2 is an elevational view of one of .the 32. The other end of the section is formed with 55 a depending portion 33 externally threaded at 34. The part II is likewise formed with a depending portion 33, externally threaded, and which is adapted to t within the recess 3| of section l2, whereby the parts are securely held in connected relation. In a like manner a number of sections may be joined to form a per- -forator of the desired length. Each section is formed with a plurality of transverse sockets or recesses which are threaded for a vportion of their length as at 35 and have formed at their inner end a powder chamber 36. 4'I'he recesses in each section are spirally arranged as will be clear by reference to Figures 1 and 4 and each recess receives a gun unit including a barrel 31 having the bore 38 for v receiving a bullet 48. 'Ihe exterior of the gun barrel 31 is threaded so' that the same is held within its recess in this manner, each barrel being provided with pin openings 4I, whereby a tool may be applied to the barrel for facilitating the operation of threading the same within its recess. It will be` observed that the I rear of the barrel extends well within its respective powder chamber, in fact each barrel extends almost to the rear wall of its powder chamber. This is desirable since it increases the length of the bore and accordingly the bullet will issue with greater force and can be more accurately directed. As shown in the drawing, the end of each bullet 48 is in direct contact with the projection 39 extending inwardly from the rear of its respective powder chamber. The projection spaces the bullet from the rear wall of its chamber and upon firing of the powder the gases generated as a result are better able to act against the rear of the bullet to discharge the same from its barrel with the greatest velocity.

In accordance with the invention this operation takes place immediately preceding the flring ofthe perforator and therefore up to this time it has been absolutely impossible to discharge any of the bullets. Even the. lling of the chambers with powder, as contemplated by the invention, is a safe procedure since it is not necessary to screw the barrels down onto a charge of explosive powder. Each powder chamber is provided with a removable plug 42 adapted to be threaded in an opening V43 formed in the perforator in alignment with a powder chamber. When the plug 42 is removed the chamber can be lled with powder through said opening. Each intermediate section is formedr with a central bore 44 extending longitudinally of the section from end to end and which is.of relatively-small diameter. The bore connects eeach of the powder chambers which are radially arranged with rpect thereto, and the upperv end of the bore in section I2 will communicate with chamber 38 containing the ring plug. As a result of the operation of lling the chambers with powder the bore 44 will likewise be lled with explosive powder which when ignited through the instrumentality of the ring plug will cause ring' of the gun units successively. For reloading the perforator following rlng of the same the parts III and II are removed as a unit from the top intermediate section I2. 'I'his removes the firing plug from its association with the ring bore 44 and thus prevents inadvertent explosion of the powder while the chambers are being lled therewith. The bores 38 in the respective barrels may be cleaned and for this purpose it is a relatively simple procedure to screw the barrel in a. direction tact with both electrodes.

to remove the same from. its transverse recess. When the bores have been cleaned and the barrels replaced or in the event this 'is found not to be necessary the next procedure is to deposit a bullet in each bore, forcing the same into the lower part of the bore by a rubber plug 45 which is allowed to remain within the bore in order to prevent water, oil or other liquid coming into contactwith and spoiling the explosive powder. The powder chambers 36 are then .filled through the openings 43, it being rst necessary', of course, to remove each of the plugs 42. In this operation some of the powder entering the chambers will of course find its way into and will fill the firing bore 44. The plug 42 for each powder rchamber is screwed into place following the filling operation but before the sections of the perforator are joined to the part I I it is necessary to insert a capsule containing explosive powder in chamber 30. The part II and the top intermediate section is then united and the perforator is ready for firing, provided the electric wires from the cable I8, namely, 46 and 41, are connected with the ground connection and ring plug, respectively.

During operations of preparing the perforator for firing it is of course understood that the switch for the electric circuit energizing the firing plug remains open. It is preferred practice to lock the switch in open position while the perforator is notin use so that the danger of premature ignition is reduced to a minimum. After the device has been inserted within a well casing and lowered by cable I8 to the required depth the switch is closed to cause energization of the fuse wire 28 having electrical con- An explosion first of all will take place within chamberl38, which results in igniting the powder in the firing bore and accordingly the bullets will be fired in succession. The bullets will puncture the well casding in ay plurality of places and due to the spiral arrangement of the gun units the said openings will be properly' oriented. After firing the perforator is hauled to the surface and may be recharged for another ring operation.

'I'he invention is not to be limited to or by details. of construction of the particular embodiment thereof illustrated by the drawing, as

various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims. L

What is claimed is:

1. In a gun type casing perforator, a body charge, each of said explosive charges being accessible from the exterior of the body portion independently of the gun units whereby the same may be loaded after said gun units are in place. and av longitudinal central ring bore extending axially of the body portion for detonating said explosive charges successively.

2. A gun type casing perforator, a body mem. ber, a cable attached to one end thereof for suspending the member and by which the same may be lowered into a. well casing, a plurality of laterally directed sockets formed in said body member and each terminating in a. powder chamber, a gun unit located within each socket, each of said powder chambers having an opening through which the same may be lled with an explosive charge, a removable plug closing each of said openings, and alongitudinal central firing bore extending axially of the body member for detonating said explosive charges successively.

3. A. gun type well casing perforator, comprising a plurality of sections forming an elongated member having a head end portion, a nose end portion, a cable attached to the head end portion for suspending the member and by which the same may be lowered into a well casing, explosive charges carried by each intermediate section of the member, a gun unit associated with each explosive charge, each of said charges being accessible from the exterior of the member independently of theV gun units whereby the same may be loaded after said gun units are in place, a longitudinal central firing bore extending axially of each intermediate section for detonating the explosive charges successively, and a ring plug in the head end portion adapted to be controlled by' an operator at a point remote from the perforator.

4. A gun type casing perforator comprising a plurality of sections forming an elongated member, said sections including a head end portion, a nose end portion and at least one intermediate section, a cable attached to the head end portion for suspending the member and by which the same may be lowered into a well casing, a plurality of laterally directed sockets formed in said intermediate section, said sockets being spirally arranged longitudinally of the intermediate section and each socket being interiorly threaded for a portion of its length and terminating at its inner end in a powder chamber, a gun unit releasably threaded within each socket, each of said powder chambers being accessible from the exterior of the section independently of the gun units whereby the same may be filled with an explosive charge after said gun units are in place, and a longitudinal central firing bore extending axially of said intermediate section from end to end thereof for detonating said explosive charges successively.

5. A gun type casing perforator, comprising a plurality of sections forming an elongated member, said sections including. a head end portion, a nose end portion and at least one intermediate section, a cable attached to the head end portion for suspending the member and by which the same may be lowered into a well casing, a plurality of laterally directed sockets formed in said intermediate section, said sockets being spirally arranged longitudinally of the intermediate section and each socket being interiorly threaded for a portion of its length and terminating at its inner end in a powder chamber, a gun unit releasably threaded within each socket, each ofsaid powder chambers being accessible from the exterior of the section independently of the gun units whereby the same may be iilled with an explosive charge after said gun units are in place, and a longitudinal central firing bore extending axially of said intermediate section and intersectingeach powder chamber whereby said explosive charges are red successively.

6. A gun type casing perforator, comprising a plurality of sections forming an elongated member, said sections including a head end portion, a nose end portion and at least one intermediate section, a cable attached to the head end portion for suspending the member and by which the same may be lowered into a well casing, Aa plurality of laterally directed sockets formed in said intermediate section, said sockets being spirally arranged longitudinally of theintermediat'e section and each socket being interiorly threaded for a portion of its length and terminating at its inner end in a powder chamber, a gun unit releasably threaded within each socket, each of said powder chambers being accessible from the exterior of the section independently'of the gun units whereby the same may be lled with an explosive charge after said gun units are in place, a firing bore extending axially of said intermediate section for firing the explosive charges successively, said head end portion having a chamber 'formed therein c'om-V municating with the upper terminal end of said firing bore, and a firing plug within said chamber adapted to be controlled by an operator at a point remote from the member.

7. A gun type casing perforator comprising a plurality of sections forming an elongated member, said sections including a head end portion, a nose end portion and at least one intermediate section, a cable attached to the head end portion for suspending the member by which the same may be lowered into a well casing, a plurality of laterally directed sockets formed in said intermediate section, a gun unit located within each socket and forming with the rear thereof a powder chamber, said intermediate section having openings formed therein leading to a powder chamber respectively through which the same may be lled with an explosive charge, a removable plug closing each of said openings, and a longitudinal central firing bore extending axially of said intermediate section from end to end thereof and intersecting said powder chambers whereby the explosive charges are fired successively.

8. A gun type casing perforator comprising a plurality of sections forming an elongated member, said sections including a head end portion, a nose end portion and at least one intermediate section, a cable attached to the head end portion for suspending the member by which the same may be lowered into a well casing, a plurality of laterally directed sockets formed in said intermediate section, a gun unit located within each socket and forming with the rear thereof a powder chamber, said intermediate section having openings formed therein leading to a powder chamber respectively through which the same may be lled with an explosive charge, a removable plug closing each of said openings, a firing bore extending axially of said intermediate section for firing the explosive charges successively, said head end portion having a chamber communicating with the upper terminal end of said ring bore, and a firing plug in said chamber adapted to be controlled by an operator at a point remote from the member.

9. A gun type casing perforator comprising a plurality of sections forming an elongated member, said sections including a head end portion, a nose end portion and at least one intermediate section, a plurality of sockets in said intermediate section, each terminating at its inner end in a powder chamber, a gun unit releasably mounted within each socket, each of said powder chambers having an opening through which the same may belled with an explosive charge after said gun units are in place, and a longitudinally extending firing bore located substanleasably mounted within each socket including a barrel extending approximately to the rear of its powder chamber, and an axial bore in said barrel for receiving aA bullet to be i'lred, each of said powder chambers having an opening through which the same may be filled with an explosive charge after said gun units are in place, and a substantially central ring bore extending longitudinally of said intermediate section from end to end thereofV for detonating the explosive charges successively.

11. A gun type casing perforator comprising a plurality of sections forming an elongated member, Said sections including a head end portion, a nose end portion and at least one intermediate section, a plurality of sockets in said intermediate section each terminating at its inner end in a powder chamber, a gun unit located within each socket and including a .barrel having abore for accommodating a bullet, the rear end of each barrel extending within its respective powder chamber whereby to provide a. bore of maximum length, each of said powder chambers having an opening through which the same may be lled with an explosive charge after said gun units are in place, and a central firing bore of relatively small diameter extending the length of said intermediate section for detonating the explosive charges successively.

l2. A gun type casing perforator comprising a4 plurality of sections forming an elongated member, said sections including a head end portion, a nose end portion and at least one intermediate section, a plurality of sockets in said intermediate section each terminating at its inner end in a powder chamber, a gun unit located within each socket and includinga barrel having an axial bore for receiving a bullet, the rear of each barrel extending within its respective powder chamber whereby to provide a bore of maximum length, and a projection extending inwardly from the rear wall oi.' each powder chamber adapted to contact its respective bullet to thereby space the same from the wall of the powder chamber.

' KUHN CALVERT. 

